• Korean Chemical Engineering Research
• /
• v.61 no.3
• /
• pp.378-387
• /
• 2023

Petrochemical is an energy consuming industry that consumes about 30% of total industrial energy consumption and is a representative carbon dioxide (CO₂) emission source. Among them, the Naphtha Cracking Center (NCC), which produces ethylene, propylene, propane and mixed C4, consumes large amounts of energy and emits significant amounts of CO₂. For this reason, an integrated techno economic- environmental impact assessment aimed at reducing energy consumption and environmental impact factors is necessary to ensure efficiency in terms of economics and environment. This study aims to analyze the efficiency of the heat exchanger network used in the existing NCC base on the pinch analysis and select an improvement plan that can reduced energy consumption. In order to reduces the utility consumption in the process, an optimal heat exchanger network considering the high-temperature and low-temperature stream was derived, and the economic evaluation was conducted by considering the trade-off between the reduction in utility consumption and the increase in heat exchanger installation cost. In addition, an environmental impact assessment was conducted on the reduced CO₂ emission in consideration of the environmental aspect, and the economic environmental impact assessment used the payback period to recover the invested funds to come up with an energy saving plan that can be applied based on the actual process. As a result of considering the economic-environmental impact assessment, when the environmental impact assessment was not considered, it was 4.29 months, 3.21 months, and 3.39 months for each case, and when considering the environmental impact assessment, it was 4.24 months, 3.17 months, and 3.35 months for each case. These results appeared equally both when the environmental impact assessment was not include and when it was include. In addition, a sensitivity analysis was conducted for each case to determine how important factors affect the payback period. As a result of the sensitivity analysis, the cost of the heat exchanger was identified as a major factor influencing the overall cost.

• Analytical Science and Technology
• /
• v.18 no.5
• /
• pp.419-424
• /
• 2005

In recent years, dioxins which were designated as persistent organic pollutants and endocrine disrupters are treated as substance of environmental pollution and studied about human health risk assessment, emission pollutants estimation, analytical methods and so on. It is easy that dioxins are accumulated to soil because of the atmosphere circulation of burning up the waste. This is the comparative studies on the distribution relationship of dioxin isomers in exhausted gas of industrial waste and urban waste incinerators, ambient air and soil. A basis of PCDDs and PCDFs based on OCDD was drawn up to the curve and they correspond to dioxin isomers in exhausted gas of industrial waste and urban waste incinerators and ambient air. On comparing these results, It was found that the ambient air and exhausted gas of industrial waste incinerators were very similar in curve and ratio. Consequently, environmental by exposed dioxin depends on the exhausted gas of industrial waste incinerators than urban waste incinerators. In case of soil, even though we can not completely rule out the possibility of pollution source bring on pesticide and other factors, and naturally biological dissociations, the curve shape is very similar to exhausted gas of industrial waste incinerators and ambient air. So, we inform here that it was mainly caused by these environmental factors.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.11 no.1
• /
• pp.45-57
• /
• 2008

The purpose of this research is to select an appropriate location of water pollution prevention facilities(WPPF) through evaluating location decision factor using environmental geographic information system. To do that, this research reviewed the current location policies of WPPFs and its related researches. And this paper builds water pollutant statistical databases, integrated them with the geographic information system of the administrative areas where water pollutants are generated, and gears it with statistical programs such as correlation and regression analysis in order to figure out the pollution factors which influence on the location decision of WPPF on the real time base. The volume of discharge of industrial wastewater is one of the most important water pollutants on the location decision of WPPF. And the number of industrial facilities also was the most important location decision factor in constructing the WPPFs. In addition, this paper noted that the number of population in each area makes a role to restraint the construction of WPPF. It identified that the disposal facility in Nackdong river upper-middle watersheds was insufficient in treating the livestock pollutants. Therefore, Gyeongbuk should concentrate on the construction of disposal facilities of livestock pollutant in these areas. The results of this research will contribute to decide what kinds of WPPF should be constructed on which watershed in Nackdong River, and to forecast the future water quality of each watershed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.11 no.2
• /
• pp.233-247
• /
• 2016

Local food industry has been spreading all over the world. Korea is also actively applying and developing local food industry. However, relatively high distribution cost in Korean agricultural market is hindering its further growth. Distribution cost has close relation with shipping distance. Raised distribution cost brings major impacts not only on quality and price of products but also on greenhouse gas(carbon dioxide) emissions. Therefore, it is necessary to find a solution for inefficient distribution system of the local food industry to reduce overall cost and greenhouse gas. In this study, we present a location selection model for local food regional center using Analytic Hierarchy Process. The location of local food regional hub center is decided based on expert opinions on five factors: accessibility, quality, population, size of area, and shipping distance. The relative importance of the five factors has been concluded as follows: quality (0.430) ${\gg}$ population (0.262) ${\gg}$ travel distance (0.201) ${\gg}$ accessibility (0.075) ${\gg}$ and area (0.033). We apply and analyze the environmental management system model for Local food industry to develop the regional hub center site selection criteria and to analyze the effects of greenhouse gas emissions in the local food industry. This study, by applying and analyzing the environmental management system of the local food industry, is believed to be a valuable asset for managing greenhouse gas emission in the local food industry. Also, the data will be used for the autonomous local food industry's direct sales stall management. Eventually, this study will contribute so greatly to the local food industry's competitiveness that even large distribution companies will give way for the local food industry.

• Journal of Korean Society of Forest Science
• /
• v.103 no.2
• /
• pp.264-269
• /
• 2014

The aim of this study was to determine the current distribution area of Robinia pseudoacacia habitat and to estimate its stand yield as well as its carbon stocks. In order to do so, the area of R. pseudoacacia distribution is obtained based on the large-scaled forest type map (1:5,000). Also, Weibull diameter distribution model is used to predict the yield of R. pseudoacacia stands. In addition, carbon emission factor is applied to calculate carbon stocks and removals. To obtain the stand yield of R. pseudoacacia, we developed estimation equation considering growth factors of the stand, e.g. mean diameter, the basal area, maximum and minimun diameter and etc. and tested it to ensure accuracy. Consequently, estimation equation derived from all growth factors have shown significance that could also be used for analysis. Site index was also established to determine the productivity of the forestland that later turned out to be ranging from 16 to 22. Based on these results, stand yield tables were drawn up. R. pseudoacacia is widely distributed in inland areas of Gyeongsang, Chungcheong and Gyeonggi provinces which covers total area of 26,770 ha. And when it is converted into carbon stocks, it amounts to 2,517,598tC with annual carbon uptake of 3.76tC/ha which is comparable to Querqus species that is known to storer large amounts of carbon. Therefore, R. pseudoacacia is also expected to serve as a viable carbon pool that would contribute to the mitigation of climate change. Furthermore, stand yield tables, an outcome of this survey would assist not only in proper management but also in sustainable management policy of R. pseudoacacia.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.5
• /
• pp.317-324
• /
• 2014

Environmental tobacco smoke (ETS) samples were collected separately in mainstream and side-stream smoke using a self-designed smoking machine, and a total 40 of PM2.5 was collected with low volume air sampler at indoor environments with and without ETS in Daejeon, Korea. About 20 trace elements including toxic metals like As, Cr, Mn, Se, V, and Zn were determined in PM2.5 and ETS samples by instrumental neutron activation analysis (INAA). It is found that the emission factors of K, Cl, Na, and Al were much higher than those of toxic elements for both mainstream and side-stream smoke. The average concentration of PM2.5 was enriched by 1.5 times at smoking area ($58.7{\pm}18.1{\mu}g/m^3$) than at smoking free area ($38.6{\pm}12.7{\mu}g/m^3$). The concentration ratio of each element between smoking and smoking free area were ranged from 1.1 to 6.0 except Cu (1.0); especially, Ce (6.0), La (5.2), K (2.3), and Co (2.0) showed higher ratio, which suggests that the ETS is one of the possible increasing factors of PM2.5 and elemental concentration at indoor environment.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.3
• /
• pp.1369-1373
• /
• 2014

Objectives: To study application of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) with $^{18}F$-FDG PET/CT for predicting prognosis of esophageal squamous cell cancer (ESC) patients. Methods: Eighty-six patients with ESC staged from I to IV were prospectively enrolled. Cisplatin-based chemoradiotherapy (CCRT) or palliative chemoradiotherapy were the main treatment methods and none received surgery. $^{18}F$-FDG PET/CT scans were performed before the treatment. SUVmax, MTV, and TLG were measured for the primary esophageal lesion and regional lymph nodes. Receiver operating characteristic curves (ROCs) were generated to calculate the P value of the predictive ability and the optimal threshold. Results: MTV and TLG proved to be good indexes in the prediction of outcome for the ESC patients. An MTV value of 15.6 ml and a TLG value of 183.5 were optimal threshold to predict the overall survival (OS). The areas under the curve (AUC) for MTV and TLG were 0.74 and 0.70, respectively. Kaplan-Meier analysis showed an MTV less than 15.6 ml and a TLG less than 183.5 to indicate good media survival time (p value <0.05). In the stage III-IV patient group, MTV could better predict the OS (P < 0.001), with a sensitivity and specificity of 0.80 and 0.67, respectively. Conclusions: Pre-treatment MTV and TLG are useful prognostic factors in nonsurgical ESC.

• Progress in Medical Physics
• /
• v.16 no.4
• /
• pp.192-201
• /
• 2005

Experiments and simulation were done to study the impact of contrast agent when CT scan was used to attenuation correction for PET Images in PET/CT system. Whole body phantom was imaged with various concentration of iodine-based contrast agent using CT. Mathematical emission and transmission density map with liver were made to simulate for whole body FDG Imaging. A variety of factors were estimated, including non-uniform enhancement of contrast agent, concentration and distribution size of contrast agent, noise level, image resolution, reconstruction algorithm, hypo-attenuation of contrast agent, and different time phases for contrast agent. Experimental studies showed that Hounsfield unit depends on the concentration of contrast agent and tube voltage. From the simulation data, contrast agents Introduced artifacts and degraded image quality on the attenuation-corrected PET images. The severity of these effects depends on a variety of factors, including the concentration and distribution size of contrast agent, the noise levels, and the Image resolution. These results Indicated that the impact of contrast agents should be considered with a full understanding of their potential problems in clinical PET/CT images.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.2
• /
• pp.657-662
• /
• 2014

Background: The epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it means that EGFR-tyrosine kinase inhibitor treatment is indicated. The purpose of this prospective study is to determine whether EGFR mutation status could be identified with reference to preoperative factors. Materials and Methods: One hundred-forty eight patients with lung cancer (111 adenocarcinomas, 25 squamous cell carcinomas and 12 other cell types) were enrolled in this study. The EGFR mutation status of each lung cancer was analyzed postoperatively. Results: There were 58 patients with mutant EGFR lung cancers (mutant LC) and 90 patients with wild-type EGFR lung cancers (wild-type LC). There were significant differences in gender, smoking status, maximum tumor diameter in chest CT, type of tumor shadow, clinical stage between mutant LC and wild-type LC. EGFR mutations were detected only in adenocarcinomas. Maximum standardized uptake value (SUVmax:$3.66{\pm}4.53$) in positron emission tomography-computed tomography of mutant LC was significantly lower than that ($8.26{\pm}6.11$) of wild-type LC (p<0.0001). Concerning type of tumor shadow, the percentage of mutant LC was 85.7% (6/7) in lung cancers with pure ground glass opacity (GGO), 65.3%(32/49) in lung cancers with mixed GGO and 21.7%(20/92) in lung cancers with solid shadow (p<0.0001). For the results of discriminant analysis, type of tumor shadow (p=0.00036) was most significantly associated with mutant EGFR. Tumor histology (p=0.0028), smoking status (p=0.0051) and maximum diameter of tumor shadow in chest CT (p=0.047) were also significantly associated with mutant EGFR. The accuracy for evaluating EGFR mutation status by discriminant analysis was 77.0% (114/148). Conclusions: Mutant EGFR is significantly associated with lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chest CT. Preoperatively, EGFR mutation status can be identified correctly in about 77 % of lung cancers.

• Nutrition Research and Practice
• /
• v.10 no.6
• /
• pp.629-634
• /
• 2016

BACKGROUND/OBJECTIVE: The aim of this experiments was to show anti-obesity effects of Korean solar salt from different salt fields in diet-induced obese mice. MATERIALS/METHODS: Diet-induced obesity (DIO) was induced by a high-fat diet (HFD; 45% cal from fat) in C57BL/6J mice for eight weeks. The mice were fed with the designated diets (chow diet for Normal, HFD for Control, 0.47%-salt-mixed HFD for purified salt (PS), Guerande solar salt from France (SS-G), solar salt from Y salt field (SS-Y), solar salts from T salt field (SS-T) and S salt field (SS-S)) for another eight weeks. We checked body weight, food efficiency ratio (FER) and tissue weights (liver and epididymal adipose tissue (EAT)), and observed serum concentrations of triacylglycerol (TG), total cholesterol (TC), leptin and insulin. We also evaluated gene expressions of adipogenic / lipogenic mRNAs of $C/EBP{\alpha}$, $PPAR{\gamma}$ and FAS and beta-oxidation-related factors ($PPAR{\alpha}$ and CPT-1) in liver and EAT. The mineral composition of salt samples were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). RESULTS: SS-T and SS-S significantly reduced body weight gain, FER, and weight of EAT compared to control and other samples (P < 0.05). SS-T and SS-S also significantly decreased serum levels of TG, TC, leptin and insulin (P < 0.05). SS-T and SS-S suppressed expressions of adipogenic / lipogenic mRNAs in liver and EAT, while promoting expression of beta-oxidation-related factors. The lowest sodium concentration was observed in SS-T ($30.30{\pm}0.59%$), and the lowest sodium-to-potassium (Na/K) ratio was found in SS-S (17.81). CONCLUSIONS: Our study shows that well-processed Korean solar salt may have anti-obesity effects in vivo, probably owing to its differences in mineral composition and other components, presumably resulting from the manufacturing processes. Further research is needed into the mechanism and to explore optimal manufacturing processes.